This level occupies the map slot MAP18. For other maps which occupy this slot, see Category:MAP18.

MAP18: Cyclone Utilities (Remember Your Birthday) is the eighteenth level of the first episode of Back to Saturn X. It was designed by Simon Judd (SlayeR), who also composed the level's untitled music track.

Sector 290: In the corridor in the far east of the map, press the northern green panel, as it lowers to allow access to the ledge. A computer area map can be found here.

Sector 592: Near the end of the long lava hallway, right before the room with the switch, an inaccessible room with two radiation suits, a medikit, an energy cell, and several armor bonuses can be seen alongside the hallway. Shoot the switch inside this room to open a hidden door nearby, revealing another switch. Press this switch to open the room with the suits.

Sector 765: In the room south-east of the red key, find the alcove with the chaingunner and the flickering lights. Press the back wall. A platform with a megaarmor lowers.

Sector 828: In the round computer room with a mancubus, jump onto the western ledge. One of the computers can be lowered to reveal a megasphere.

Sector 1098: Next to the exit, turn right and jump from the high platform to the nearby ledge and turn left to find an opening. Inside is a large room with dead bodies, a rocket launcher, and elevators leading up to three soul spheres.